Sickle grinding machine



March 1955 E. NORWOOD ET AL 2,703,950

sIcxLE GRINDING MACHINE Filed April 30, 1951 2 Sheets-Sheet 1 will /7 20I J2 i ZZLJVorwood L.fi.3nemman INVENTORS,

BY I ATTORNEYS- March 15, E NORWOOD ETAL 51cm; GRINDING MACHINE FiledApril 30, 1951 2 Sheets-Sheet 2 EL. JVorwoad Zflfinemaman INVENTORSATTORNEYS United States Patent '0 2,703,950 SICKLE GRINDING MACHINEErnest L. Nor-wood and Lloyd D. Brennaman, Ewing, Nebr.

Application April 30, 1951, Serial No. 223,714

2 Claims. (Cl. 51-125) This invention relates to a machine designed forgrinding blades of sickle bars, the primary object of the inventionbeing to provide a machine which will sharpen and recondition the bladesof a sickle bar with a be'vel corresponding with the beveled cuttingedges of new sickles.

An important object of the invention is to provide a machine of thischaracter on which a sickle bar may be secured in such a way that theblades of the sickle bar may be engaged by the side faces of thegrinding stones of the machine to properly grind the desired bevel orcutting edges of the blades.

A still further object of the invention is to provide a sickle grindingmachine wherein the grinding stones of the machine may be adjusted tovarious angular positions with respect to the blades of the sickle barbeing conditioned for insuring accurate grinding.

Another important object of the invention is to provide a sicklegrinding machine including a vertically swinging grinding head, meansbeing provided for automatically moving the grinding head to a positionaway from the sickle bar being ground, when the pressure on the grindinghead necessary to hold the grinding stones to their work, has beenrelieved.

With the foregoing and other objects in view which will appear as thedescription proceeds, the invention consists of certain novel details ofconstruction and combinations of parts, hereinafter more fully describedand pointed out in the claims, it; being understood that changes may bemade in the construction and arrangement of parts without departing fromthe spirit of the invention as claimed.

Referring to the drawings:

Figure 1 is a front elevational view of a sickle grinding machineconstructed in accordance with the invention illustrating a sickle baras mounted thereon.

Fig. 2 is a plan view thereof.

Fig. 3 is an end elevational view of the machine with the grinding headmoved to its inactive position.

Fig. 4 is a plan view illustrating the sickle support as swung to aposition for engagement by one of the grinding stones of the machine.

Fig. 5 is a sectional view taken on line 5-5 of Fig. 3.

Referring to the drawings in detail, the machine comprises the standindicated generally by the reference character 5, the stand comprisingthe legs 6 and post 7 rising therefrom. Secured at the upper end of thepost 7 is the tubular section 8 which is provided with openings 9adapted to register with openings 10 of the hollow post 11 that extendsdownwardly from the forward end of the adjustable grinding head support12. A pin 13 is provided and is adapted to be extended through thealigning openings of the tubular section 8 and hollow post 11, securingthe grinding head support in various angular positions with respect toits work.

Pivotally mounted on the grinding head support, is the grinding head 14which is in the form of a pair of spaced arms connected at their forwardends where the bearings 15 are provided, in which the grinding stoneshaft 16 operates, the ends of the grinding stone shaft 16 extendingbeyond the bearings, as clearly shown by Fig. 4 of the drawings. Thegrinding stones are indicated by the reference character 17 and aresecured at the ends of the grinding stone shaft 16. The grinding headalso provides a support for the electric motor 18, which is providedwith the pulley 19, over which the belt 20 operates, the belt ice 20also operating over the sheave 21 which is secured to the shaft 16, sothat rotation of the shaft 16 and grinding stones 17 will be provided bythe operation of said motor.

Extending from one end of the grinding head 14, is the arm 22, to whichone end of the coiled spring 23 is secured, the spring 23 having itsopposite end secured to the post 7 through the medium of the hook 24.This spring 23 is so tensioned that under normal conditions or when thegrinding head is not in use, the grinding head will be tilted rearwardlyto the position as shown by Fig. 3 of the drawing, or away from itswork. It will be obvious that with slight pressure directed to thegrinding head, the grinding head will be moved downwardly bringing thegrinding stones into contact with the blades of the sickle bar beingsharpened.

Extending forwardly from the tubular section 8 of the machine, are thespaced bolts 25, to which the vertical supporting bar 26 is secured, theupper end of the supporting bar 26 being attached to the horizontalsupporting member 27 which includes a wide bar of inverted V-shape incross section, to which the rods 28 are connected at their outer ends,the rods 28 having their inner ends connected to the vertical supportingbar 26.

The support for the sickle bar indicated at 29 being sharpened, is inthe form of a carriage 30 of inverted V-shape construction fitted overthe horizontal supporting member 27 to slide longitudinally thereof. Thecarriage or support 30 is provided with clamps 31 within which thesickle bar 29 to be ground is secured as by means of set screws 32.

In the use of the grinding machine, the sickle bar to be ground ispositioned in the clamps 31 and is secured within the clamps by the setscrews 32. The grinding head support is now moved to a position to bringone of the grinding stones thereof into engagement with one edge of oneof the blades of the sickle bar. The pin 13 is now positioned to holdthe brinding head support in its adjusted position. The grinding stoneis now set in motion and the right hand cutting edge of the blade isengaged by the left side face of the stone grinding or sharpening theright hand cutting edge of the blade. After the sharpening of the bladeedge, the grinding head is elevated and the carriage or support 30 ismoved a distance to bring the right hand cutting edge of the adr jacentblade opposite to the grinding stone, which has been moved adjacent tothe sickle bar. This operation is continued until the right hand edgesof all of the blades of the sickle bar have been properly ground.

The grinding head is now lifted and adjusted or rotated to bring theopposite grinding stone to a position for engagement with the left handcutting edges of the blades, and a pin 13 is positioned through thealigned openings of the post 8 and hollow post 11, thereby securing thegrinding head against movement in a horizontal plane sliding the sicklebar carriage along its support, it is obvious that the left hand cuttingedges of each sickle bar blade may be properly ground. After thegrinding operation it is obvious that the sickle bar may be readilyremoved and another sickle bar positioned within the carriage forgrinding.

In view of the foregoing, it is believed that the construction andoperation of the sickle bar grinding machine will be obvious, and thatfurther detailed description is unnecessary.

Having thus described the invention, what is claimed is:

1. In a sickle grinding machine, a stand, a support mounted on the standcomprising a wide horizontal bar of inverted v-shape cross section, aninverted V-shaped carriage on which the sickle bar being ground ismounted for sliding movement longitudinally of said support, a grindinghead support mounted on the stand for pivotal movement in a horizontalplane, a grinding head mounted on said grinding head support, a powershaft mounted on the grinding head, normally disposed in parallel spacedrelation with said sickle bar support, a grinding stone secured on eachend of said power shaft, said stones adapted to be manually moved intocontact with cutting edges of the blades of the sickle bar being ground,and means for normally swinging the grinding head upwardly away from thesickle bar with respect to the grinding head support.

2. A sickle grinding machine comprising a stand including a verticalpost, a tubular member secured to the upper end of said post, a clampsecured to said tubular member adapted to clamp a sickle bar inhorizontal position with the blades thereof disposed upwardly, agrinding head support, a hollow post depending from said grinding headsupport and rotatably fitted in the tubular member, said tubular memberand hollow post having aligning openings, a pin extending through saidaligning openings securing the grinding head support in its positions ofhorizontal adjustment, a grinding head pivotal- 1y mounted on thegrinding head support for vertical swinging movement, grinding stonesmounted on the grinding head adapted to grind the blades of the sicklebar mounted in the clamp, a spring connected between the grinding headand stand normally biasing the grinding head and stones upwardly awayfrom the sickle bar, 1

and means for operating the grinding stones.

References Cited in the file of this patent UNITED STATES PATENTS ScottOct. 13, Hefft Aug. 15, Dutton Aug. 4, Dutton Aug. 15, Gilson June 25,Fachman Oct. 5, Cooney May 1, Brown et a1. Apr. 4, Cotfeen Oct. 25,

FOREIGN PATENTS Germany May 24, France Dec. 12,

